Safety device for gas-supply apparatus.



G. P. PIGOT.

SAFETY DEVICE FOR GAS SUPPLY APPARATUS.

APPEIUATION FILED DEO.18, 1911.

Patented Nov. 11, 191-3.

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barren sra ras GERMAIN r'nnnnnrorioor, or ranrsrna'non.

SAFETY DEVICE on GAS-SUPPLY AFPBABATUS.

Specification of Letters-iatent.

Patented Nov. 11, 1913.

Application'filed December 18, 1911. Serial No. 666,543,

To all whom it may concern:

Be it known that I, GERMAIN FRn DnRIo P1001, a citizen of the FrenchRepublic, residing at Paris, Department of the Seine, in France, haveinvented certain new and useful Improvements in or Relating to SafetyDevices for Gas-Supply Apparatus; and I do hereby declare the followingto be afull, clear, and exact description of the invention, such as willenable others skill'ed in the art to which it appertains to make andusethe same.

The present invention has for its object the provision of a safetydevice particularly applicable to gas conduits and intended toautomatically cut off the supply or" gas it a leakage occurs in the gaspipe This apparatus comprises a valve opening inversely to the flow ofgas and balanced by means of a counterweight adjustable in such a manneras to hold the valve open in normal operation. In case of an importantleakage at a point beyond the valve, the valve is applied to itsseatowingtothe reduction of pressure due to said leakage.

There is arranged in-t-he apparatus in ad-' advance of the principalvalve in, such manner as to cause theprincipal valve to close when the.auxiliary valve falls back.

upon its seat. Figs. 2, 3 and 4 show in section slightly modifieddevices.

gas entering through aconduit .51 connected with the main pipe. reachesa chamber 52 ftiOIl .74. Normally, the rod 65 bears upon ithePI'OJGCtiOIl 59 and holds the valve 7 to its seat. Through an opening44, thecham- 'ber 43 communicates with the chamber 19. At the lower partof this last-named chamber or at some other place there is arranged adischarge. nipple 4 to which a pipe may be connected to conductthe gasto the desired place. This nipple maybe provided with a cook, ifdesired.

Above the' chamber l9, there isarranged a knob 48 integral with a rod.49 and acted upon by a counter-spring 50" or equivalent device. When theknob" 48 is depressed the end of the rod 49 bears upon the extremity ofthe threaded rod of the counter-weight13.

The operation is as follows: Normally, when gas is being admitted to theapparatus, ifthe vertical valve 7 is opened by pressing on the knob 48,theggas lifts the horizontal valve 54, and the latter remains raised solong as the valve 7 permits of the passage of gas to the utilizationapparatus'ff. The valve 7 remainsiopen under the action ofcounter-weight 13,.so long as the pressure is substantially equal onboth sides thereof. It a breakagesh'ould occur in the pipe beyond thesafety apparatus, the pressure in the pipe on the outletside of theapparatus is reduced: and under the influence of the pressure of the gasinadvance of the device (which is greater than atmospheric pressure),the valve 7closes and instantaneously prevents the escape of gas. If,'onthe other hand, the supply of gas is stopped for any reason, thehorizontal valve 54 is no longer supported by the excess pressure frombe neath' it, and when it falls backup'on its seat, the rod 65 bearsupon the projection 59, and thereby closes the valve 7. 'In order In the.device represented in Fig; 1,,the I to restart the apparatus, the knob48 is pressed, the rod ofthe counter-weight 13 is thus pressed back bymeans of the rod 49, and, consequently the valve 7 is unseated. It willbe seen that .in this construction, the valve 54 cannot rise if thepassage of a current ofjga's hasnot been produced by opening the valve 7because a counter-pressure is established above this valve, which doesnot form a perfect joint. I v

In the construction shown in Fig. 2, the gas entering through the pipe51 reaches the chamber 52, the bottom of which carries a cylindricalsocket 66 providedwith perforations 53". In this socket, a piston valve54 is mounted for reciprocation. To the valve 54', there is pivoted arod 60 pivoted to one of the arms 62 of a bell-crank lever 46. The

bell-crank lever 46 is pivoted to the top of a supporting rod 63.Through the openings a 58, the chamber 52 communicates with the chamber43 in which there is arranged the principal valve 7 provided withathreaded weight 13.

around a shaft 64 in a support fixed to the rod 12 carrying anadjustablecounter- This rod is mounted to oscillate wall of thechamber 43. Thevalve also car- 46, rests. Through an opening 44, the

I ranged to which piping or tubing'may be ries a projection 59 uponwhich the member 61 forming the counter-weight of the lever chamber 423communicates with a chamber 19 at the lower part of which a nipple isar- .lever 46 to operate the piston valve 54 which uncovers theapertures 53. Simultaneously, theweight 61 is lifted, and releases thevalve 7, which opens under the influence of the counter-weight 13; Thegas passing through the openings 53 holds the piston valve 54 in place;the pressure being substantially equal on both sides of the valve 7, itwill remain open, due to the counter-weight 13., The gas passing throughthe nipple 4 is conducted to the utilization 7 '5 apparatus. If the pipeshould break beyond the safety apparatus, the pressure in the outletportion of the pipe falls, and under the influence of the gas pressureon the inlet 7 side thereof, the valve 7 closes and prevents the: escapeof gas. If, on the other hand, thesupply of gas should stop foranyreason, the piston valve is no longer acted upon by the excess pressureof the gas and moves back under theinfiuence of the weight 61, whichthen bears upon the projection 59 of the valve 7 and serves to apply itto its seat. Consequently, when the supply of gas is re- 7 established,the valve 7 remains closed and j the gas cannot escape to the exterior.

} It will be noted that when the knob 48 is depressed, the weight'61 ismoved to substantiallya vertical position and its center of gravityistherefore shifted closer to the axis of the bell crank lever 46. Theforce couple tending to rotate the weight around the axis of the bellcrank leveris therefore very slight. On the contrary, when the valve isclosed, a relatively large force is necessary to. raise the weight 61,because the force couple is greater, due to the fact that the center ofgravity of the weight is farther from the axis of the bell crank lever.It is seen, therefore, that when the valve is once closed by thelowering of the weight, the reestablishment of the gas supply Will haveno effect in lifting the weight 61, but when said valve has once beenopened, the pressure of the gas supply is sufiicient to hold the weightin the raised position, due to the fact that the center of gravitythereof is nearer to the axis of the bell crank lever than in the closedposition of the Valve. In order to furnish a supply to the utilizationapparatus again, it is necessary to actuate the rod 49, as describedabove.

The device illustrated in Fig. 3 is a modification in which the valve 7is suspended from the wall of the chamber 43. As in the deviceillustrated in Fig. 1, this valve carries an adjustable counter-weight13 and also a counter-rod 59 upon which the counterweight 61 of thelever 46 bears. The operation of this valve is identical with thatillustrated in Fig. 2. 1

Fig. 4 represents a modification of the valve shown in Fig. 2. This isconstituted by a hemispherical valve 7 connected with a threaded rodpivoted to a support 64 and carrying two counter-weights 13 and 13'. Thecounter-weight 13 which is movable upon the threadedrod 12 receives theextremity of the counter-weight 61 carried by the bell-crank lever 46.

hat I claim is 1. Safety valve mechanism comprising a casing throughwhich the medium to be controlled flows, an inlet and outlet in saidcasing, a counter-balanced valve therein, said valve adapted toautomatically close when the pressure of the medium at the inlet end ofthe casing exceeds to a predetermined extent that at the outlet end butadapted to remain open when said pressures are equal, and meansinterposed in the path of the incoming medium and operable when the flowof medium ceases to close said valve.

2. Safety valve mechanism comprising a casing through which the mediumto be controlled flows, an inlet and outlet in said casing, acounter-balanced valve therein, said valve adapted to automaticallyclose when the pressure of the medium at the inlet end of'the casingexceeds to a predetermined extent that at the outlet end but adapted toremain open when said pressures are equal, means interposed in the pathof the incoming medium and operable when the flow of medium ceases toclose said valve, and manually operable means to open said valve.

3. Safety valve mechanism comprising a casing through which the mediumto be controlled fiows, an inlet and outlet in said casing, acounter-balanced valve therein, said valve adapted to automaticallyclose when the pressure of the medium at the inlet end of the casingexceeds to a predetermined extent that at the outlet end but adapted toremain open When said pressures are equal, a pivotally mounted elementin the casing having engagement With said valve and normally tending toclose the same, said element disposed in the path of the incoming mediumthe pressure of Which holds said element in a position that permits saidvalve to remain open, said element 10 adapted to automatically operatewhen the In testimony whereof I aifix my signature, in presence of twoWitnesses.-

GERMAIN FREDERIC PICOT.

Witnesses:

H. (100x15, EMILE KLOTZ.

Copies of this patent may be obtained for five cents each, by addressingthe Commissioner of I'atents,

Washington, D. 0. a

